Norovirus has reportedly struck about a dozen California GOP staffers at the Republican National Convention.

California GOP chairman Jim Brulte said no delegates or alternates have shown signs of the highly contagious illness and will continue to attend the convention, The Washington Post reported.

The California delegates are staying at the Kalahari Resort in Sandusky, Ohio, which is about 60 miles from the convention site at Quicken Loans Arena in Cleveland. They also had plans to visit Cedar Point amusement Park in Sandusky and the Pro Football Hall of Fame in Canton, Ohio.

The illness is believed to have initiated with one staffer, who was sickened in California, and spread to 12 of the 36 staffers, who began showing symptoms on Thursday, according to the Post.

The staffers arrived at the convention site ahead of the delegates, causing concerns about the possibility of spreading the disease, which causes stomach and intestinal inflammation, diarrhea and vomiting.

Convention attendees have been instructed to wash their hands diligently and avoid shaking hands and sharing food, The Sacramento Bee reported.

Large dispensers of hand sanitizer were on hand at a delegate breakfast, and delegates were instructed to stay off buses if they feel any symptoms.

Erie County health commissioner Peter Schade, who is investigating the outbreak, said officials are awaiting test results to confirm their suspicions about the disease, Reuters reported.

"It looks like Norovirus. We're not 100 percent sure," he said.

Those who are sick are staying in their hotel rooms to avoid spreading the disease. The virus often spreads in confined spaces such as cruise ships, hospitals and universities.

Symptoms of the infection, which include "explosive bouts of vomiting and diarrhea" typically last only one to three "very miserable" days, Scientific American noted.

The outbreak sparked a rash of jokes on Twitter.

In a gift to comedians everwhere, the RNC is making people sick. Norovirus.Which triggers vomiting and diarrhea. https://t.co/GadzUpJmfj